Conductive pads are located over a top of an interconnect structure in order to provide electrical connections to a separate die, package or interposer for forming a three-dimensional integrated circuit (3DIC). In order to reduce the risk of oxidation of the conductive pads, passivation layers are deposited over the conductive pads.
As technology nodes decrease, a pitch between conductive pads decreases. As a result, passivation layers having a higher degree of conformity, i.e., uniform thickness of the passivation layer, are used to protect the conductive pads. In some instances, the passivation layers are formed using a high density plasma chemical vapor deposition process (HDPCVD). HDPCVD generates charged particles and these charged particles are directed toward the conductive pads during deposition of the passivation layer over the conductive pads.